Surgeons meet challenges of removing rock-hard cataracts

Whether in a senior citizen with diabetes or in a young patient who suffered a traumatic injury, rock-hard cataracts pose a challenge to remove and need extra postoperative steps to ensure proper recovery.

Young or old, good vision or poor vision, it can be a surprise which patients have a brunescent cataract, OSN Cataract Surgery Board Member Sumit “Sam” Garg, MD, said. Even in patients whose vision is “passable,” in the 20/60 to 20/70 range, the lens may be more dense than it appears.

Good visual potential

A dense cataract does not diminish the patient’s potential for good vision after surgery. A careful examination of the lens and of the corneal endothelium helps determine the patient’s risk for corneal edema and how long it may take vision to recover after surgery, Garg said.

Source: Sumit “Sam” Garg, MD

“When I examine the patient, I use LOCS (Lens Opacities Classification System) for grading my lenses. I’m looking at color, opalescence, cortical changes and subcapsular changes, trying to grade each one individually. The more brunescent it is, it is likely more dense,” he said.

Garg said he stays vigilant for coexisting problems.

“If the cataract is hypermature, you worry about the capsule running out. If there is any risk of zonulopathy, you need to be cognizant and prepared for that,” he said.

And he gets to know his patients so they can determine together the best path forward regarding surgery.

“I always ask, ‘What is the best you’ve ever seen, and when is the last time you saw that?’ If they say, ‘Hey you know, doc, I saw well up until 2 years ago, then things started to go downhill, but before that I had very good vision,’ then that changes my approach with respect to considering an advanced technology lens. If the cataract is really dense and I don’t have a good way of assessing visual potential, I’ll mention the extended depth of focus and presbyopia-correcting lenses, but I’ll often steer away from those to make sure I give the patient the best chance to see well with the most predictability,” Garg said.

Preoperative exam is crucial

It is typical of patients with this type of cataract to wait until they can barely see light before coming in for an exam, Zaina Al-Mohtaseb, MD, an OSN Cataract Surgery Board Member, said.

At the preoperative appointment, patients must be warned of the higher risk for corneal edema postoperatively, higher risk for complications and delayed healing, she said.

“Clinically, I look for asymmetry in the density of the lens between eyes that can point to zonular loss. I also look at the dilation because many times these cases also have small pupils. Preoperatively I typically get a B-scan to evaluate for gross retinal pathology since there is a poor view to the retina in these dense cataracts. Sometimes it is difficult to get good IOL calculations using optical methods, so we might have to do immersion for axial length measurements,” she said.

A slit lamp can be used to examine a patient to determine the density of the cataract. It is important to note if the back of the eye can be viewed during the examination, OSN Cataract Surgery Board Member Jeffrey Whitman, MD, said.

If the back of the eye in not viewable during a slit lamp examination, Whitman said the patient’s vision potential is unknown. Some surgeons would send these patients to a retina specialist for a posterior ultrasound exam to determine whether the retina is attached.

“Others feel you should get the cataract out so you can see the back of the eye and go from there,” Whitman said. “I’m not saying one way is better than the other, but it’s often something that’s done preoperatively in these patients if you can’t see the back of the eye.”

Note the cataract color

In older patients, a 60-plus-year-old patient for example, it is important to brighten up the slit lamp beam when looking at a cataract. A normal-appearing white cataract may have a brownish or yellow color under its surface, a sign of a dense cataract, which can only be seen with a bright slit lamp beam, Whitman said.

Rock-hard cataracts typically appear yellow or brown on examination due to the accumulation of the photooxidation pigment urochrome. A surgeon needs to assess the visual potential of the eye and the lens opacity to determine the likelihood of a successful cataract removal, Foster and colleagues wrote in a study in Journal of Cataract and Refractive Surgery.

The color of the cataract is also helpful in determining the surgical path, Healio.com/OSN Section Editor Uday Devgan, MD, said.

Source: Nicole R. Fram, MD

“The first thing we do with a patient with a very dense cataract is judge the density by seeing how brunescent it is. How brown is it? Some of the worst ones we call a root beer cataract because root beer is so brown it’s almost black. The other option we look at is the opacity. How opaque is the whole thing? Sometimes it can have that dark intensity, but you can still see through it, like a glass of iced tea. Or the cataract could be totally opaque,” he said.

Trauma can also induce a brunescent cataract, so the lens support and zonular structures need to be thoroughly evaluated. Patients who have these induced rock-hard cataracts can have zonular weakness, which will be an issue intraoperatively, Devgan said.

Minimizing complications

Surgically, the goal for a dense cataract is to remove the lens while minimizing endothelial damage, avoiding wound burn and intraoperative complications, and minimizing postoperative inflammation, Al-Mohtaseb said.

Often, patients with these types of cataracts have small pupils. Using intracameral epinephrine, Shugarcaine or dilation devices such as iris hooks or Malyugin rings (MicroSurgical Technology) can help during surgery, she said.

“Given the density of the cataract, a poor red reflex can impede visualization of the capsulorrhexis and can also result in the surgeon tearing the edge with the chopper. Using trypan blue can significantly help this step. After the rhexis, given the density and size of the lens, one has to be careful with the volume and speed of fluid injected during hydrodissection to avoid capsular block and blowing out the posterior capsule,” she said.

FLACS is appropriate

Femtosecond laser-assisted cataract surgery is an effective surgical option for these lenses, according to OSN Cataract Surgery Board Member Audrey R. Talley Rostov, MD.

A femtosecond laser for either a brunescent dense cataract or a white intumescent cataract can be used to perform a safer and more accurate capsulotomy, she said.

“The reason is that you can program the capsulotomy, and sometimes, oftentimes, in very dense cataracts, or even in a white intumescent cataract, you can see zonular issues where there can be zonular weakness. For example, in a white intumescent cataract, you can see an Argentinian flag sign, which refers to the capsulotomy extending out, and that’s because of pressure when you’re doing your capsulorrhexis or capsulotomy,” Talley Rostov said.

Even with a dense cataract, the laser can typically do some degree of phacofragmentation and divide the lens into smaller pieces, or at least begin the process, she said.

Perfect capsulotomy

Dense and white cataracts can lead to an increased risk for an incomplete anterior capsulotomy, and the rate of posterior capsule tears is close to 11%, according to a study by Taravella and colleagues in Journal of Cataract and Refractive Surgery.

A femtosecond laser creates the capsulotomy in a closed system and minimizes pressure differences between the lens and anterior chamber. A manual capsulotomy and standard phacoemulsification can increase traction on weakened zonular fibers and possibly create or extend a zonular dialysis, Taravella reported in the study.

Femtosecond laser allows for a perfect capsulotomy in a dense cataract where visibility is poor, Whitman said.

“We always think about this in mature white cataracts, where we can put VisionBlue (Dutch Ophthalmic Research Center) in them, stain the capsule, and that helps us make the capsulotomy. But when they’re dark brown, even the VisionBlue doesn’t often give us contrast, and it’s still hard to tear that capsulotomy. The femtosecond laser doesn’t care; as long as you can focus on the capsule itself, it will make a very nice capsulotomy for you. You may not be able to do much else because it may be too dense for your femtosecond laser to penetrate into, but sometimes it will penetrate enough to give us good cleavage planes to break up this very dense cataract,” he said.

Whitman said he first tries to score down into the cataract, making radial femtosecond incisions, and then uses the phacoemulsification setting for a denser nucleus. This is basically a higher-power, different pulse ratio to try to cut into the hard cataract.

If it is possible to score down halfway into the lens, Whitman then uses a bimanual chopping instrument to break the lens in half.

“It saves me phaco time and unnecessary inflammation of the eye,” he said.

More phaco energy expended in the eye generates more heat and turbulence, increasing the chance of a cloudy cornea the day after surgery, he said.

Garg said he uses the Catalys system (Johnson & Johnson Vision) when a patient dilates moderately well because the system’s specialized fragmentation pattern can help during the procedure. In addition, the imaging system can identify violation of the posterior capsule in patients who have undergone vitrectomy.

“Even starting those cleavage planes in some of those super dense cataracts, it can be helpful in reducing the overall manipulation in the eye and energy use,” he said.

Talley Rostov said she uses the Centurion Vision System (Alcon) with torsional phacoemulsification as an efficient way to dissolve and phacoemulsify dense cataracts. She uses one of two techniques during nuclear disassembly, either a vertical chop of the cataract or a gentle carve out of the lens.

“Using the efficiency of the Centurion, I make an initial groove and then get the instruments in to do a vertical chop. I also use bimanual cataract surgery technique. For this, I find the fluidics are very controlled. I sometimes decide to do more of a gentle carve out, so I’m not pushing it all, but rather just letting the phaco machine and the fluidics kind of carve out the lens in a very controlled manner. I’m able to get in some viscoelastic to create a plane on the very hard leathery shell of the cataract to get it out of there,” she said.

Susceptibility to wound burn

Patients with dense cataracts are more susceptible to corneal wound burn due to the high level of ultrasound energy in the eye. The high degree of friction used during the procedure can burn the eye quite easily, Devgan said.

A dispersive viscoelastic can protect the corneal endothelium during cataract removal, but the endothelium should be recoated up to three times during the surgery to keep the cells protected, he said.

“To divide up the cataract, the tough part is, there can be a thick posterior plate. It’s very fibrous, and some of these cataracts don’t chop so easily. Normally when you do phaco chop, when you chop or split a cataract, it’s kind of like dry firewood. You only need to start to crack it a little bit, and then you can get through it and it’s done. It’s easy to split dry firewood. But a brunescent cataract can be like wet firewood — it doesn’t want to split. It can be fibrous, almost leathery. It’s quite difficult to split. That’s why I go behind the cataract and try to crack that posterior plate first,” Devgan said.

A manual extracapsular extraction can also be considered. This procedure involves no phacoemulsification energy going into the eye, and it is an easy method to extract the cataract in one piece, he said.

However, it is a more involved surgery with a larger incision. A phacoemulsification incision is typically between 2 mm and 2.8 mm wide, whereas an extracapsular incision is between 8 mm and 10 mm, Devgan said.

“The incision we make for the extracap is also in the sclera. You’re going to need some cautery, a stitch or two, to close the incision. It’s a more involved surgery and a little bit more traumatic for the patient. That large incision is going to induce a lifetime of at least 2 D of astigmatism. After the cataract is out, if you’re able to put a lens in the capsular bag, that’s ideal, but if not, you put it in the sulcus,” he said.

miLOOP is helpful

A newer tool that has been useful in dense cataract procedures is the miLOOP (Iantech), a device that uses nitinol filament technology to perpendicularly encircle the nucleus and slice through the cataract when the surgeon closes the loop, Whitman said.

“This is a miracle for these hard cataracts. You slip the lasso around the cataract, cinch it and break it into two or more pieces very easily, usually without a lot of turbulence in the eye. You’ve broken the lens up, and you have not used any phaco power at this point in this dense nucleus,” he said.

The miLOOP provides a twofold benefit during dense cataract procedures, Garg said. First, it gives a clean chop so the surgeon does not have to reach around the lens and put stress on the zonules.

“Second, it helps with making sure the lens is free from the capsule; you get really nice movement of the lens. I think there’s a lot of benefit for the miLOOP in really dense cataracts, especially for people who don’t chop,” he said.

Postoperative protocol

Postoperatively, patients will experience more inflammation than they would after a normal cataract surgery. Eyes can sustain corneal edema due to the amount of phacoemulsification energy used in the procedure, so more than a topical steroid is necessary to control the inflammation, Devgan said.

Talley Rostov said she uses a regimen of Lotemax (loteprednol etabonate ophthalmic suspension 0.5%, Bausch + Lomb) twice daily and a branded NSAID, such as Prolensa (bromfenac ophthalmic solution 0.07%, Bausch + Lomb), once daily.

“With a denser cataract, where I’m expecting more corneal edema, more inflammation, I’ll go to four times daily on that or a stronger steroid, such as Durezol (difluprednate ophthalmic emulsion 0.05%, Alcon). Also, depending on the surgery itself, I always want to make sure that if there is more wound manipulation, which can happen in these longer cases, that the wound is watertight. There’s a greater chance I’ll put in a 10-0 nylon suture,” she said.

Patients need to understand that recovery will be longer than for a normal cataract procedure. They may see a fog postoperatively because of edema and swelling, so an aggressive steroid protocol is needed, Garg said.

Garg said he prescribes prednisolone acetate ophthalmic solution four times a day for a week for a routine cataract patient, but a patient with a dense cataract may need the solution six times a day with a salt water drop (2% or 5% sodium chloride) if swelling persists.

“It’s OK to tell a patient that their recovery will be longer. Everyone says, ‘Well, my neighbor had cataract surgery and saw the next day,’ but every cataract isn’t the same. If you take a few minutes to counsel them, that will save a lot of their frustration postoperatively. I think most of the patients are super grateful and very happy with the improvement in their vision and mostly the quality of life afterward,” he said. – by Robert Linnehan

• References:
• Devgan U. Approach to the dense brunescent cataract. https://cataractcoach.com/2018/05/07/approach-to-the-dense-brunescent-cataract/. Published May 7, 2018. Accessed Aug. 15, 2018.
• Devgan U. Dense brunescent cataracts present surgical challenges. https://www.healio.com/ophthalmology/cataract-surgery/news/print/ocular-surgery-news/%7Bd249a6d3-5826-4336-86d4-5558a8f1f67e%7D/dense-brunescent-cataracts-present-surgical-challenges. Published June 25, 2011. Accessed Aug. 16, 2018.
• Foster GJL, et al. J Cataract Refract Surg. 2018;doi:10.1016/j.jcrs.2018.03.038.
• Hahn P, et al. Eye (Lond). 2016;doi:10.1038/eye.2016.109.
• Ianchulev T, et al. Br J Ophthalmol. 2018;doi:10.1136/bjophthalmol-2017-311766.
• Taravella MJ, et al. J Cataract Refract Surg. 2016;doi:10.1016/j.jcrs.2016.02.049.

• For more information:
• Zaina Al-Mohtaseb, MD, can be reached at Baylor College of Medicine, 1 Baylor Plaza, Houston, TX 77030; email: zaina1225@gmail.com.
• Uday Devgan, MD, can be reached at Devgan Eye Surgery, 11600 Wilshire Blvd. #200, Los Angeles, CA 90025; email: devgan@gmail.com.
• Sumit “Sam” Garg, MD, can be reached at University of California, Irvine, 850 Health Sciences Road, Irvine, CA, 92697-4375; email: gargs@uci.edu.
• Audrey R. Talley Rostov, MD, can be reached at Northwest Eye Surgeons, 10330 Meridian Ave. N., Suite 370, Seattle, WA 98133; email: atalleyrostov@nweyes.com.
• Jeffrey Whitman, MD, can be reached at Key-Whitman Eye Center, 11442 N. Central Expressway, Dallas, TX 75243; email: whitman@keywhitman.com.

Disclosures: Al-Mohtaseb reports she is a consultant for Alcon, Bausch + Lomb and Johnson & Johnson. Devgan reports no relevant financial disclosures and that he owns and runs the CataractCoach.com website, which is free and noncommercial. Garg reports he is a consultant for Allergan, Zeiss and Johnson & Johnson. Talley Rostov reports she is a consultant for Alcon and Bausch + Lomb. Whitman reports he is a speaker for Alcon and Bausch + Lomb.

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